Fair Value Measurements (Details) (USD $)	6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Financial Assets:
Financial Assets: Natural Gas Options/Swaptions	$ 5,000,000	$ 8,000,000
Financial Liabilities:
Financial Liabilities: Crude Oil Swaps	157,000,000	17,000,000
Financial Liabilities: Crude Oil Options/Swaptions	170,000,000	110,000,000
Financial Liabilities: Natural Gas Options/Swaptions	11,000,000
Financial Liabilities: Foreign Currency Rate Swap		40,000,000
Financial Liabilities: Interest Rate Swap		1,000,000
Proved Oil and Gas Properties Carrying Amount	95,000,000
Proved Oil and Gas Properties Written Down During the Period - Fair value at End of Period	20,000,000
Pretax Impairment Charges for Proved Oil and Gas Properties	75,000,000
Pretax Impairment Charges for Proved Oil and Gas Properties, in which EOG utilized an accepted offer from a third-party purchaser	56,000,000
Aggregate Principal Amount of Current and Long-Term Debt	5,890,000,000	5,890,000,000
Estimated Fair Value of Debt	6,323,000,000	6,222,000,000
Fair Value, Inputs, Level 1 [Member]
Financial Assets:
Financial Assets: Natural Gas Options/Swaptions	0	0
Financial Liabilities:
Financial Liabilities: Crude Oil Swaps	0	0
Financial Liabilities: Crude Oil Options/Swaptions	0	0
Financial Liabilities: Natural Gas Options/Swaptions	0
Financial Liabilities: Foreign Currency Rate Swap		0
Financial Liabilities: Interest Rate Swap		0
Fair Value, Inputs, Level 2 [Member]
Financial Assets:
Financial Assets: Natural Gas Options/Swaptions	5,000,000	8,000,000
Financial Liabilities:
Financial Liabilities: Crude Oil Swaps	157,000,000	17,000,000
Financial Liabilities: Crude Oil Options/Swaptions	170,000,000	110,000,000
Financial Liabilities: Natural Gas Options/Swaptions	11,000,000
Financial Liabilities: Foreign Currency Rate Swap		40,000,000
Financial Liabilities: Interest Rate Swap		1,000,000
Fair Value, Inputs, Level 3 [Member]
Financial Assets:
Financial Assets: Natural Gas Options/Swaptions	0	0
Financial Liabilities:
Financial Liabilities: Crude Oil Swaps	0	0
Financial Liabilities: Crude Oil Options/Swaptions	0	0
Financial Liabilities: Natural Gas Options/Swaptions	0
Financial Liabilities: Foreign Currency Rate Swap		0
Financial Liabilities: Interest Rate Swap		$ 0